Simulating a structurally simple model of a manufacturing enterprise revealed complex dynamic behavior. Enterprise modeling and simulation provided estimates of end-of-life inventory and order delivery performance based on interactions of forecast quality, quoted product availability, material procurement and safety stock policies, vendor lead times, product life cycle, and part commonality. An unexpected result was that end-of-life inventory can exist even under ideal environmental conditions. Prospective applications of these methods include estimating the effects of incremental improvements, verifying impacts of process changes, and generating enterprise behavior information. by M. Shahid Mujtaba† Can we understand the potential impacts of process changes? Can we quantify the expected amount of improvements and benefits? Can we anticipate the effects of environmental changes? Can we predict the effects and side-effects of making